1. Field of the Invention
This invention relates to an electrocardiographic electrode for deriving a weak voltage from a person and, more particularly, to an electrocardiographic electrode having a structure, in which a water-proof suction member for covering the electrocardiographic electrode held in close contact with a person's skin is strongly bonded to the electrocardiographic electrode so that it will not be detached therefrom.
2. Prior Art
As is well known in the art, electricity generated in a person is induced by the activity of the heart, brain, muscles, etc.
Particularly, electricity induced in the heart is derived and recorded as a weak voltage induced on the person's skin using an external electrocardiograph. When the electrocardiograph is used, its input section is electrically coupled to the person. To this end, electrocardiographic electrodes have to be held in close contact with the person's skin.
A prior art electrocardiographic electrode which is held in close contact with man's skin in use will now be described with reference to FIGS. 4 to 6. FIG. 4 is a perspective view of electrocardiographic electrode 1. The electrocardiographic electrode has a substantially circular, viscous base member 2. The viscous base member 2 is a doughnut-like woven cloth member having a central aperture or opening 3. Its back side, which is held in close contact with the person's skin M as shown in FIG. 6, is viscous. The opening 3 of the viscous base member 2 is closed by an electrode support 4, which consists of a hard synthetic resin and is formed on the top or front side of the viscous base member 2. A magnetic lead coupler 5 projects from the front surface of the electrode support 4. An electrode member 6 is secured to the lower or back surface of the lead coupler 5. The electrode member 6 is held in direct contact with the person's skin M to derive a weak voltage from the person's heart.
FIG. 5 shows the back side of the lead coupler or connector 7. A lead 10 is coupled to the lead coupler 7 for leading the heart's weak voltage derived by the electrode member 6 through the lead 10 to the electrocardiograph (not shown). The lead connector 7 has substantially the same size as the electrocardiographic electrode and is made of a hard resin. It has a recess 8 formed on the back side. A magnetic electrode coupler 9 is accommodated in the recess 8 and secured to the bottom thereof. One end of the lead 10 is connected to the electrode coupler 9, and its other end is connected to the electrocardiograph (not shown).
To obtain an electrocardiogram using the electrocardiographic electrode 1 having the above construction, the viscous base member 2 of the electrode 1 is bonded to a person's skin M, as shown in FIG. 6. Then, the lead connector 7 is coupled to the electrocardiographic electrode 1 with its magnetic electrode coupler 9 magnetically attracted to the lead coupler 5 of the electrocardiographic electrode 1. In this state, a heart's weak voltage derived by the electrode member 6 is coupled through the lead 10 to the electrocardiograph (not shown) for recording.
While the electrocardiographic electrode 1 is held in close contact with the patient's skin for obtaining a patient's electrocardiogram, it is liable that the lead connector 7 coupled to the electrode 1 is detached from the electrode due to an unconscious movement, e.g., a tossing-about in sleep. In such a case, noise is produced so that an accurate electrocardiogram can no longer be obtained.
Further, the patient sometimes unconsciously pulls out the lead 10 extending from the lead connector 7. If the lead 10 is pulled extremely strongly, again detachment of the lead connector 7 from the electrocardiographic electrode 1 results, so that an accurate electrocardiogram can no longer be obtained.
Further, the patient may take a bath with electrocardiographic electrodes held in close contact with the skin. Also, an electrocardiogram is sometimes produced while the patient is making a physical exercise, e.g., swimming. In such cases, a water-proof suction member is used to cover the electrocardiographic electrode together with the lead connector. However, it is liable that the water-proof suction member is detached by the action of water so that an accurate electrocardiogram can no longer be obtained.